1. Technical Field
The present invention relates in general to the field of printers, and in particular to paper tape receipt printers. Still more particularly, the present invention relates to a receipt printer having a scissor cutter that is adjustable to create either a full or partial cut across paper tape.
2. Description of the Related Art
Point-Of-Sale (POS) receipt printers typically use roll paper on which sales receipts are printed. After being printed, the sales receipt is separated from the rest of the paper roll by either an automatic cutter or a manual tear bar. With most automatic cutters, the receipt is not cut across the entire width of the paper roll. Rather, a small length of uncut paper is left so that the paper does not fall out of the printer and onto the counter or floor. The uncut portion of the paper is then torn by hand, and the receipt is handed to the customer. Alternatively, there are some applications where a full cut is desired, such that a smooth edge is provided across the entire bottom edge of the receipt, and for situations in which multiple receipts must be neatly stacked after exiting the printer.
It is often desired that a same printer be able to produce either a fully cut or a partially cut paper receipt. This is accomplished in various ways in the prior art. For example, U.S. Pat. No. 4,981,059, issued Jan. 1, 1991 to Kobayashi, and U.S. Pat. No. 6,302,605 B1, issued Oct. 16, 2001 to Kanbe, teach the use of a rotary cutter, which is a small wheel that rolls along a grooved support, which can vary the cut length by stopping the wheel in different locations. Alternatively, U.S. Pat. No. 5,505,552, issued Apr. 9, 1996 to Hasegawa et al, teaches the use of a guillotine cutter that advances a guillotine blade to a first position to produce a partial cut, or advances to a second position to produce a full cut.
A system that uses an adjustable scissor cutter is described in U.S. Pat. No. 6,347,896 B1, issued Feb. 19, 2002 to Robinson. This system teaches the use of a fixed blade that is mounted to a fixed chassis. A moving blade, that articulates across a cutting edge of the fixed blade, is adjustable, such that repositioning a cutting tip of the moving blade defines the length of the cut across the paper tape. However, this arrangement requires a complex system of slots and crank pins to reposition the moving blade, which makes the system susceptible to misalignment and mechanical jamming.
What is needed, therefore, is an improved system for adjusting the cutting width of a scissor cutter across a paper roll. Preferably, such a system would be easily adjusted with minimal impact on operational moving components.